Part of my drawing disappears depending on perspective/zoom
Here are some possibilities;

As a quick fix you could try and set the Candy object strokes setting to 3D Location if it's not already. By default they're set to 2D Layers and this is generally the more useful setting but 3D might resolve your issue here. (Object Data properties - Strokes - Stroke Depth Order)

I would guess that the issue is because your object is set to 2D Layers and has items in the foreground and background/different planes. Blender can struggle calculating whether you want the image as a foreground or background image if you have items in different places, especially if the settings are set to 2D Layers mode (as above). Try separating each drawing on a different visual plane into their own objects (to separate tab into edit mode, use the  B key to border select the drawing, then  P to separate).

Sometimes if you try and draw in the wrong orientation (object set to draw on front and you try and draw on the side) blender adds a nasty invisible line through it which confuses it's layering. ↹ Tab into Edit Mode, use  A to select all, all the vertices should be highlighted now, You might see a line that shouldn't be there. Deleting it should resolve layering problems.